Work roll automatic spacing means

ABSTRACT

An apparatus for automatically causing the work rolls of a rolling mill to be spaced apart during roll changing. The apparatus disclosed comprises vertical plungers in the shape of rods longer in length than the height of the lower work roll chocks which extend through the lower chocks. The plungers are biased upwardly by springs. The upper ends of the plungers protrude well above the lower chocks and remain in contact with the upper chocks during roll separation. The length of the plungers is such that their lower ends automatically recede into the chocks on roll separation permitting a roll carriage to be inserted beneath the chocks. When the chocks are lowered onto the carriage, the plunger lower ends bear against the carriage, and the protruding upper ends hold the upper chocks spared from the lower chocks.

, United States Patent [72] Inventor Glenn Paul Moffett Salem. Ohio [2|] Appl. No. 843,646 [221 Filed July 22,1969 [45] Patented June 29, 197] [73] Assignees Gull 8: Western Industrial Products Company Grand Rapids, Mich.

[54] WORK ROLL AUTOMATIC SPACING MEANS 7 Claims, 1 Drawing Fig.

[52] US. Cl 72/238, 73/359,136/230 [51] Int. Cl r. B2lb3l/08. GOlk 7/04;l (50] Field of Search 72/238, 239; l36/230 [56] References Cited UNITED STATES PATENTS 1,936,672 11/1933 lversen et al .r 72/238 X 2,037,210 4/1936 Buente 72/239 Primary Examiner-Travis S. McGehee Attorney-Meyer, Tilberry and Body ABSTRACT: An apparatus for automatically causing the work rolls of a rolling mill to be spaced apart during roll changing. The apparatus disclosed comprises vertical plungers in the shape of rods longer in length than the height of the lower work roll chocks which extend through the lower chocks. The plungers are biased upwardly by springs. The upper ends of the plungers protrude well above the lower chocks and remain in contact with the upper chocks during roll separation. The length of the plungers is such that their lower ends automatically recede into the chocks on roll separation permitting a roll carriage to be inserted beneath the chocks. When the chocks are lowered onto the carriage, the

plunger lower ends bear against the carriage, and the protruding upper ends hold the upper chocks spared from the lower chocks.

PATENTEuJumlsn 3,589,161

INVENTOR. E GLENN P. MOFFET BY Ww 7' 6 ATTORNEYS.

WORK ROLL AUTOMATIC SPACING MEANS The present invention is directed toward the rolling mill art and, more particularly, to apparatus for facilitating roll changing in a rolling mill.

The invention is particularly applicable to changing work rolls in a four-high mill, and will be described with particular reference thereto; however, it will be appreciated that the invention is capable of broader application and could be used in many types of mill installations. I Four-high mills include a pair of upper and lower work rolls, and larger diameter upper and lower backup rolls above and below the work rolls. Each roll has a pair of end chocks in which it is rotatably mounted. The work roll chocks preferably are nested into recesses in the respective backup roll chocks. The latter are retained in tl'ldmill housing windows in any suitable manner. 7 l v i In order to remove the work rolls from the mill, it is necessary first to extend the roll stack separating the work rolls from the backup rolls and from each other. This is generally accomplished by a plurality of hydraulic cylinders between the chocks for all of the rolls, or in other ways. Following roll separation, a roll changing carriage is inserted beneath the lower work roll chocks, and the latter arethen lowered onto the carrier. a

To keep the roll surfaces of the work rolls apart during the roll changing step, it has been the practice to manually position four steel spacer blocks between the chocks for the work rolls. Alternatively, it was known to use a spacer pin between the chocks and an air-operated, springreturn plunger to hold or retain the spacer pin in its proper position.

Several disadvantages were experienced with the use of spacer blocks. For example, the storage problem around the rolling mill, and in addition, if an operator forgot to remove the blocks before rolling, the blocks were crushed, or alternatively, the necks of the rolls were broken. With the airoperated plungers, outside power was required to operate them. Additionally, air hoses were required to be disconnected and reconnected for each roll change. Operating valves and controls were also required adding additional cost and maintenance time to the mill operation.

These and other disadvantages are overcome in accordance with the present invention, wherein there is provided, in a mill of the type having upper and lower work rolls and end chocks therefor, the improvement comprising automatic spacing means including a pair of spaced-apart vertically oriented plungers in the shape of rods longer in length that the height of the lower work roll chocks positioned in each of the lower roll chocks. The plunger include an upper end engageable with the upper work roll chocks and a lower end normally extending below the lower surface of the lower roll chocks and engageable with a roll changing coverage inserted beneath the chocks. Means are provided to bias the plungers upwardly.

Prior to roll changing, the work rolls are separated. The plungers automatically move upwardly during roll separation remaining in contact with the upper chocks, the lower ends of the plungers receding into the lower chocks. This permits a roll carriage to be inserted beneath the chocks.

When the entire roll assembly is lowered onto the roll carriage, the lower ends of the plungers bear against the carriage, and the upper rolls are held spaced from the lower rolls by the plunger protruding upper ends.

in the case where backuprolls are provided above and below the work rolls, the chocks for the work rolls fit into recesses in the backup roll chocks. Preferably, holes are pro vided in the lower backii'proll chocks to receive the plunger lower ends when the work rolls are positioned close together in work engaging relationship.

Also in accordance with a preferred aspect of the invention the lower surfaces of the upper work roll chocks include spaced sockets in which the plunger upper ends are seated.

Accordingly it is an object of the present invention to provide an automatic spacing means for spacing work rolls during work roll changing.

It is a further object of the present invention to overcome the disadvantages of prior spacing means, and in particular to eliminate the need of manual spacer blocks, hose connections, valves, controls and the like.

The invention and advantages thereof will become apparent upon consideration of the following specification, with reference to the accompanying drawing, in which the FIGURE shows, in section, an automatic spacing means in a four-high mill. On the left-hand side of the centerline in the FIGURE, the mill rolls are in normal operating positions; and, on the right-hand side of the centerline, the roll stack is extended preparatory to roll changing.

Referring now to the drawing, wherein the showings are for the purpose of illustrating the preferred embodiment of the invention only, and not for the purpose of limiting the same, the FIGURES show a four-high mill A including upper and lower work rolls B and C, and above and below the work rolls, upper and lower backup rolls D and E. The automatic spacing means in accordance with the present invention is broadly indicated with the letter F, and on the right-hand side of the centerline, there is shown a roll changing carriage G beneath the lower work roll C. v

The only part of the mill housing which is shown is one of the end frames 12 of the housing defining the usual window 14. The window is adapted to contain large upper and lower chocks l6 and 18 for the upper and lower'backup rolls D and E. These chocks come close together at surfaces 20,22, and inside of the surfaces, the chocks together define upper and lower recesses 24 and 26 which receive the chocks 28 and 30 for the upper and lower work rolls, respectively. By means of cooperating bearing surfaces at 32 and 34 for the four chocks, the work roll chocks 28 and 30 are vertically slidable within the recesses 24 and 26, from the nested position shown on the left-hand side of the centerline, to the stack extended position illustrated on the right-hand side of the centerline. In the latter position, the work roll surfaces 36 which are normally adjacent surfaces 38 of the backup roll chocks are spaced vertically from the backup roll chocks.

The backup roll chocks 16,18 are releasably retained in the window in any suitable manner. The work roll chocks 28,30 are readily removable, with the work rolls, through one of the windows 14 of the housing. To remove the work rolls, the roll stack is expanded to separate the rolls and chocks of the mill. This involves raising the upper backup roll D and the two work rolls. The amount the backup roll is raised is sufficient to permit the work rolls to be spaced from each other and from each of the backuprolls.

This spacing of the rolls can be accomplished in a number of ways, but in the mill shown, the upper backup roll D is lifted away from the lower backup roll E by means of backup roll balance cylinders 40, two for each pair of backup roll chocks. These balance cylinders are suitably connected to a source of hydraulic pressure, to raise pins 42 within the cylinders in a known manner. Normally the balance cylinders act against the pressure of a screw-down mechanism (not shown) for downward adjustment of the chocks and roll gap, but in the present instance they are also used to spread the upper backup roll and lower backup roll chocks.

With the backup roll chocks spaced apart, the work roll chocks can then be moved apart from each other, and from the backup roll chocks. This is accomplished in the mill shown by means of work roll lifting cylinders 44 (a pair for each pair of work roll chocks). These lifting cylinders are positioned in the lower backup roll chocks l8, and are supplied with hydraulic fluid by hydraulic lines 46 connected to the balance cylinders 40. Within the work roll lifting cylinders are lift pins 48 which engage the lower side 36 of the lower work roll chock 30. Actuation of the lift pins 48 raises the lower work roll chocks relative the lower backup roll chocks to the position shown at the right of the centerline. Within the lower work roll chocks 30, are roll contour cylinders 48. The roll contour cylinders 48 are also connected to a suitable source of hydraulic fluid. The cylinder pins 50 engage the undersides of the upper work roll chocks 28. Actuation of cylinder 48 raises the pins 50 to space the upper work roll chocks from the lower work roll chocks.

The particular spacing of the rolls and roll chocks depends upon design criteria. A critical spacing is that between the lower backup roll chocks l8 and the lower work roll chocks, there should be sufficient space to accommodate carriage G. The latter is rolled into position beneath the lower work roll chocks on laterally extending track 52 which is positioned near the bottom of the recess 26 in each of the lower backup roll chocks.

Following expansion of the roll stack and insertion of the roll changing carriage, the pressure within the lifting cylinders 44 is released, lowering the lower work roll chocks onto the roll changing carriage G. Normally, prior to this step, spacing blocks were placed between the work roll chocks 28 and 30 to hold them in spaced elevated positions, since, during roll changing, the pressure within the roll contour cylinders 48 is of necessity released.

In accordance with the present invention, the work roll chocks 28 and 30 are held in a spaced apart relationship by means of the automatic spacing means broadly indicated with the letter F. The spacing means could take a variety of configurations but according to the preferred embodiment, each spacing means comprises a steel plunger 54, which is an elongated bar stock member. Each plunger is positioned in a vertically oriented hole 56 in the lower work roll chocks, and two spaced-apart holes and plungers therein are provided in each chock. The holes extend all the way through the chocks, and the plungers are of sufficient length to have their upper and lower end portions 58 and 60 capable of being exposed above and below the upper and lower surfaces of the chocks. Plunger 54 thereby acts as a force transmitting means between upper end portion 58 and lower end portion 60. The diameters of the holes near the lowermost ends 62 thereof are such as to engage the plungers with a sliding fit, whereas the upper portions 64 of the holes are of larger diameter to accommodate an annular washer 66 welded to the plungers, intermediate the ends thereof. The larger diameter portions of the holes define seats for an annular coil spring 68 which engages the washer to bias the plunger upwardly. The upper ends of the holes are enclosed with annular retainers 70 which align the plungers for vertical movement within the holes.

The upper ends 58 of the plungers are seated in sockets 72 formed in the underside of the upper work roll chocks, whereas the lower ends 60 of the plungers drop downwardly into sockets 74 formed in the upper surface of the lower backup roll chocks, the sockets 74 being of slightly greater depth than those in the upper work roll chocks.

Normally, when the work roll chocks are close together, the upper chocks 28 force the plungers 54 downwardly into the sockets 74 as shown in the view on the left-hand side of the centerline.

In operation, when the roll stack is expanded by the plurality of hydraulic cylinders, the plungers 54 ride upwardly remaining in contact with the upper work roll chocks 28 biased by the annular coil springs 68. The length of the plungers is such that when the roll stack is fully extended the plungers lower ends 60 recede into the lower work roll chocks 30 until the ends are recessed slightly within the holes 62 or flush with the lower surfaces of the chocks. This permits the work roll changing carriage G to be rolled beneath the lower work roll chocks without obstruction by the plungers. When the hydraulic pressures are released in the lifting and roll contour cylinders 44 and 48, not only are the lower work roll chocks 30 lowered onto the carriage, but also the upper work roll chocks are lowered until the plunger lower ends 60 bear against the carriages.

This automatically holds the upper work roll B in a position spaced from the lower work roll C for removal of both rolls from the mill, the length of the plungers being dictated by the amount of roll separation required.

After disengaging the hydraulic connections the work roll assemblies are retracted from the mill.

When preparing a work roll assembly to be placed into the mill, the lower roll chocks are located on the roll changing carriage. The upper roll chocks are then lowered onto the four plungers giving a positive location and proper alignment for entry into the mill.

ln the case of work roll changer failure, the four spring loaded plungers can be depressed manually, and a pin can be inserted in hole in the plungers to hold the plungers down. The top work roll assembly may then be removed from the mill by a balance bar or any other method available in the mill area.

It is apparent that the present invention provides a novel means for automatic spacing of the work rolls and work roll chocks which overcomes the disadvantages of prior art mechanisms, and in particular, an improved means by which the storage of loose blocks, or the need for external hydraulic connections with the work rolls chocks for roll spacing is avoided.

Although the invention has been described with reference to a specific embodiment, variations within the scope of the following claim will be apparent to those skilled in the art.

Having thus described my invention, I claim:

1. An automatic spacing means for a rolling mill having upper and lower rolls and end chocks therefor, comprising a pair of spaced-apart vertically oriented plungers positioned in each of the lower roll checks;

the plungers including upper ends engageable with the upper work roll chocks and lower ends extendable normally below a lower surface of the lower work roll chocks and engageable with a roll-removing means on which said lower surface seats; and,

means for biasing said plungers upwardly.

2. The spacing means of claim 1 wherein the length of the plunger lower ends extending below said lower surface of the lower work roll chocks is proportional to the spacing desired between the upper and lower work roll chocks during roll changing.

3. The spacing means of claim 1 wherein said biasing means is a coil spring.

4. A rolling mill comprising upper and lower work rolls;

end chocks for said rolls;

spaced-apart vertically oriented holes extending through each of the lower work roll chocks;

plunger means positioned in each of said holes;

means biasing said plunger means upwardly;

the plunger means each comprising an upper end engageable with the upper work roll chocks and a lower normally protruding end extending below a lower surface of the lower work roll chocks engageable with a roll removing means on which said lower surface seats;

the length of said protruding end being proportional to the desired spacing of the roll chocks during roll changing.

5. The rolling mill of claim 4 including socket means in the lower surfaces of the upper work roll chocks in which the upper ends of said plunger means are seated.

6. The rolling mill of claim 5 including upper and lower backup rolls and end chocks therefor, the backup roll end chocks defining recesses in which the work roll chocks are seated, the upper surface of the lower backup roll chocks including track means on which a roll changing means is positioned within the mill, the upper surface of said lower backup roll chocks defining sockets which receive the plunger means lower ends.

7. An automatic spacing means for a rolling mill having at least one pair of upper and lower rolls and end chocks therefor, comprising:

generally vertically oriented plunger means extending through each lower roll chock;

6 said plunger means including first end means engageable when said roll removing means :is in position a force is with said upp r r ll h k n second end means transmitted from said second end means through said tendable below a lower surface of the lower roll checks when said chocks are in a first normal working position for engagement with a roll removing means on which said 5 lower chock rests during roll removal;

said plunger means further including a force transmitting portion between said first and second end means whereby force transmitting means to said first end means such that said upper roll chocks are forced by said first end means into a spaced-apart relationship with said lower roll chocks. 

1. An automatic spacing means for a rolling mill having upper and lower rolls and end chocks therefor, comprising a pair of spaced-apart vertically oriented plungers positioned in each of the lower roll chocks; the plungers including upper ends engageable with the upper work roll chocks and lower ends extendable normally below a lower surface of the lower work roll chocks and engageable with a roll-removing means on which said lower surface seats; and, means for biasing said plungers upwardly.
 2. The spacing means of claim 1 wherein the length of the plunger lower ends extending below said lower surface of the lower work roll chocks is proportional to the spacing desired between the upper and lower work roll chocks during roll changing.
 3. The spacing means of claim 1 wherein said biasing means is a coil spring.
 4. A rolling mill comprising upper and lower work rolls; end chocks for said rolls; spaced-apart vertically oriented holes extending through each of the lower work roll chocks; plunger means positioned in each of said holes; means biasing said plunger means upwardly; the plunger means each comprising an upper end engageable with the upper work roll chocks and a lower normally protruding end extending below a lower surface of the lower work roll chocks engageable with a roll removing means on which said lower surface seats; the length of said protruding end being proportional to the desired spacing of the roll chocks during roll changing.
 5. The rolling mill of claim 4 including socket means in the lower surfaces of the upper work roll chocks in which the upper ends of said plunger means are seated.
 6. The rolling mill of claim 5 including upper and lower backup rolls and end chocks therefor, the backup roll end chocks defining recesses in which the work roll chocks are seated, the upper surface of the lower backup roll chocks including track means on which a roll changing means is positioned within the mill, the upper surface of said lower backup roll chocks defining sockets which receive the plunger means lower ends.
 7. An automatic spacing means for a rolling mill having at least one pair of upper and lower rolls and end chocks therefor, comprising: generally vertically oriented plunger means extending through each lower roll chock; said plunger means including first end means engageable with said upper roll chocks and second end means extendable below a lower surface of the lower roll chocks when said chocks are in a first normal working position for engagement with a roll removing means on which said lower chock rests during roll removal; said plunger means further including a force transmitting portion between said first and second end means whereby when said roll removing means is in position a force is transmitted from said second end means through said force transmitting means to said first end means such that said upper roll chocks are forced by said first end means into a spaced-apart relationship with said lower roll chocks. 